Steam-engine.



J. STUMPF..

STEAM ENGINE.

APPLICATION FILED NOV. 16, 1910.

Patented June 6, 1911.

J OHANN STUMPF, Oli' BERLXN, GERMANY.

STEAlt-ENGNE.

Specification of Letters Patent.

Patented June 6, 1311.

Application filed November 16, 1910. Serial No. 592,704.

' To all whom t muy concern: l

Be it known that l, .loiiANN STUMPF, a subject of the Emperor oi ('lrer1nany'resid ing at 33 Kurfrstendamm, Berlin lV., Germany, have invented certain new and useful improveuients in Unidirectional- Flow Steanrlngines, of which the following is a specification. l

This invention relates to uni-directional flow steam engines, that is engines in which the working steam enters the` cylinder at one end and exhausts through ports in the cylinder covered and uncovered by the pist0n at and near the end ot' its Working stroke. ln such engines the steam once it has entered the cylinder never vreturns on its path before exhausting therefrom, hence the naine uni-directional flow. In such engines the points at which release and compression begin are never varie'd so that when starting or when running at high loads, an engine properly designed for its ordinary normal load, willrgive excessive compression. To avoid this I propose to employ an auxiliary exhaust valve and the present invention relates to a novel construction of auxiliary exhaust valve Which is automatic in operation and may be effectively and simply cut out at times when not required. By cutting out my auxiliary exhaust valve in this way, when not required, the said valve does not interfere with the economic working of the engine during normal running.

The invention is illustrated in two con venieiit modifications in the accompanying drawings and the novel features of this invention will be pointed out in the claims.'

In the. drawings :-Figure l is a vertical section through theeylindcr of an engine having anvauxiliary exhaust valve according to one form of this invention. is a section similar to Fig. 1 and showing another form of the invention. Fig. 3 is a detailed view ot the automatic valve ein ployed in Fig. 2. p y

In carrying the invention into effect aceording to the form illustrated the engine cylinder a Ain which the piston lz moves, has, leading from the region of the inlet end, an

exhaust passage c which is controlled by a.

cock c. The exhaust passage c opens into a casing Z1 in which a steam operatedvalve f is adapted to move. Leading from the inlet end of the cylinder there is a pipe d having a valve d and this pipe opens into. the end,

Fig. 2

of the casing b. lfhe steam controlled valve f comprises two pistons connected Vby acentral narrow neel; and the distance apart of the,v piston parts f f is such that when one ofthe ports c is open, the other is closed.

The operation of this device is as follows During starting the cocks c d are opened. lVhen the steam is passed through one `of the main steam valves, m` for instance, the

high pressure steam passes into the cylinder and also through the pipe d to the casing b. The valve fis Sin consequence pressed to the left, so that the left-hand exhaust port c is uncovered and the steam from the left-hand end of the cylinder a may not only exhaust, through the ports p in the cylinder which are controlled by the piston but also throughV the auxiliary exhaust passage ato the casing brand thence to the auxiliary exhaust outlet la. This state of affairs continues until the compression pressure on the left-hand side of the piston lc is greater than the steam pressure on the right-hand side of the piston k. Since the compression pressure is not allowed to rise very quickly owing to the exhaust passage c being open, this auxiliary exhaust Will continue for a very considerable part of the stroke from right to left and thereby only a very low compression will end of the cylinder but. only in the region of the inlet end the piston Pc in its strokel as can be seen at the right-hand side of the '7 ligure, Acovers the auxiliary exhaust passage- Which is thereby automatically cut out so that sutlcient compression is secured to in- 9a sure proper cushioning and also to insure that the valve f is operated by inlet steam before the passage c 'is uncovered at the inlet end by the piston. In this way it is impossible that` live steam can escape through the auxiliary exhaust passage c. The point at which the auxiliary exhaust pipe c" opens into the cylinder may be determined by the conditions under which the engl is in# tended to work. I

According to the form of this invention illustrated in Figs. 2 and 3 l omit the: pipes c in Fig. 1 and modify the construction of the valve. Accordinglto this form the main exhaust taires place from ports g which are 'controlled by the piston g at and near the end of its Working stroke. The auxiliary,

gine Works as an or inary uni-directional flow steam engine. When starting or during overloads and it is desired to reduce the com ression the cocks s are opened by means of t cir actuating rod s-. When Working steam enters the cylinder it passes by the pipe 7' to one side of the double valve t and presses that side against its seat thereby opening the opposite valve part t. During the Working stroke of the piston Q therefore steam may escape in the position shown in Fig. 1 through the left-hand pipe 7' past the left-hand valve part t to the exhaust outlet'a. When again steam is admitted at the left-hand end of the cylinder,

that is necessary is for the operator to close .the cocks s.

the left-hand valve part t closes against its seat and the same process as described above takes place past the right-hand valve part t. It Will be seen that this construction is exceedingly simple and in order to cut out the automatic auxiliary exhaust valve all It is to be noted that with the arrangement described the right-hand valve part t will only be pressed to its seat with full pressure so long ually subjected to increasing pressure.

as admission continues, while the left-hand valve part Will be gradengine increased the automatic double valve 'will therefore gradually decrease ineffective action' as the speed of the engine increases so that even if by neglect the cocks s are left opened the ordinary normal operation of the engine is not seriously interfered with.

4In order however to obtain maximum Ietliciency at normal, running th'e cocks s should be closed.

l. In a double actin uni-directional iovv steam engine, in combination with a cylinder having inlet ports at its ends and separate exhaust ports arranged about the een ter of the cylinder, a piston adaptedto overrun and control said exhaust ports at and near the end of its Working stroke, a steam operated auxiliary exhaust valve, connections leading from about the ends of the cylinder to opposite sides of said valve, and closing members in said connections.

2. In a uni-directional flow steam engine, in combination with a cylinder having inlet ports at its ends and separate exhaust ports arranged about the center of the cylinder, a piston adapted to overrun and control said exhaust ports at and near the end of its Working stroke, a double valve, having oppositely faced valve parts articulated together, a casing in which said valve is mounted and guided, an outlet from said casing and disposed between said valve arts, connections leading from about the ends of the cylinder to opposite sides of said casing and cocks in said connections.

In witness whereof I have hereunto set my hand in the presence of two witnesses.

y JOHANN STUMPF. Witnesses:

W. WINTER,

' H. Boum. 

